Fabric three-dimensional draping performance evaluation method

Abstract

The invention discloses a fabric three-dimensional draping performance evaluation method, and belongs to the technical field of fabric performance evaluation, and the method comprises the steps: scanning a fabric three-dimensional draping form, constructing a triangular mesh model, and calculating the three-dimensional draping performance of a fabric according to the three-dimensional coordinates of all vertexes in the triangular mesh model; dividing the triangular mesh model into a plurality of independent and non-intersected triangles by using a triangulation algorithm; calculating the area of each triangle and the position data of the centroid of each triangle according to the three-dimensional coordinate of the vertex of each triangle, and calculating the three-dimensional draping performance evaluation index of each triangle according to the position data of the centroid of each triangle; and calculating a three-dimensional draping performance evaluation index of the fabric according to the three-dimensional draping performance evaluation index of each triangle and the area of each triangle, and evaluating the three-dimensional draping performance of the fabric through the three-dimensional draping performance evaluation index of the fabric. The method can solve the problems that a traditional two-dimensional projection method cannot capture wrinkle details and is insufficient in quantification precision, and realizes accurate quantification and stable evaluation of the draping performance.

Description

Technical Field

[0001] The invention relates to a method for evaluating the three-dimensional drape performance of a fabric, and belongs to the technical field of fabric performance evaluation. Background Art

[0002] The drape property of a fabric is a core indicator for measuring its appearance, performance, and practical value. It directly affects the aesthetic appeal of clothing, the drape of decorative fabrics, and the morphological stability of industrial fabrics. Currently, the drape property of fabrics is primarily evaluated using standard testing methods (such as the umbrella projection method). While this method is simple to use, it has technical drawbacks.

[0003] The umbrella projection method is essentially a two-dimensional evaluation method. Its main drawback lies in the lack of information dimension: by calculating the drape coefficient solely based on the projected area, key morphological features such as the distribution of wrinkle depth and changes in surface curvature in three-dimensional space are lost. This makes it impossible to record the morphological evolution of the dynamic wrinkle formation path of the fabric from flat to stable during the draping process. Research has shown that two fabrics with the same projected area can exhibit completely different actual drape effects due to differences in wrinkle distribution, such as concentrated wrinkles versus uniform wrinkles. Furthermore, the two-dimensional method is susceptible to interference from environmental factors such as lighting and shooting angle, resulting in poor measurement data stability.

[0004] While the drape testing devices proposed in Chinese patent publications CN209495975U, CN205826536U, and CN2321002Y utilize various sensing or imaging technologies, such as cameras and laser scanning, their core evaluation methods are still based on static geometric parameters calculated from two-dimensional projections or simplified models, such as projected area, contour radius, and drape coefficient. These methods fail to transcend the framework of two-dimensional representation and are unable to capture and quantify the true three-dimensional geometry of fabrics. Consequently, they lack a deep understanding of the essential physical processes of drape, particularly those related to deformation energy.

[0005] Chinese patents with publication numbers CN213517141U and CN209495975U attempt to optimize the testing process, but their evaluation core is still limited to the two-dimensional projection framework: both use automated means (single-chip microcomputer timing control / mechanical position adjustment) to improve the operational efficiency of the umbrella projection method, but completely inherit the two-dimensional static evaluation paradigm, and the final output is still the overhang coefficient derived from the projection area. Chinese patent with publication number CN209495975U only expands the clamping point position but does not go beyond the geometric calculation of the overhang angle. This path dependence on traditional methodology means that it is still a technical improvement within the two-dimensional evaluation system, unable to reach the core dimensional transition of three-dimensional displacement field analysis, and does not solve the problem of the lack of core dimensions in the dynamic evaluation of overhang performance. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for evaluating the three-dimensional drape performance of fabrics, which can solve the problems that the traditional two-dimensional projection method cannot capture wrinkle details and has insufficient quantification accuracy, and realize accurate quantification and stable evaluation of drape performance.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for evaluating the three-dimensional drape performance of a fabric, comprising: Scan the three-dimensional drape of the fabric to construct a triangular mesh model, and then use the triangulation algorithm to divide the triangular mesh model into several independent and non-intersecting triangles based on the three-dimensional coordinates of all vertices in the triangular mesh model; Calculating the area of ​​each triangle and the position data of the centroid of each triangle according to the three-dimensional coordinates of the vertices of each triangle, calculating the three-dimensional drape performance evaluation index of each triangle according to the position data of the centroid of each triangle, calculating the three-dimensional drape performance evaluation index of the fabric according to the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluating the three-dimensional drape performance of the fabric according to the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

[0008] In combination with the first aspect, further scanning the three-dimensional drape form of the fabric and constructing a triangular mesh model includes: Cut a circular fabric sample with no creases, no damage and smooth edges within a preset distance from the edge of the fabric, cut a positioning hole at the center of the fabric sample, and evenly stick several reflective marking points on the surface of the fabric sample; Align the center of the fabric sample with the center of the upper and lower clamping plates of the drape tester. Pass the positioning pins of the lower clamping plate through the positioning holes of the fabric sample and the center hole of the upper clamping plate in sequence. Clamp the fabric sample so that the fabric sample maintains a natural three-dimensional drape without pulling. Scan the fabric sample at multiple angles to obtain the complete three-dimensional drape data of the fabric sample; Generate an initial triangular mesh model based on the complete three-dimensional drape shape data of the fabric sample; The initial triangular mesh model is repaired with holes and cleaned with non-manifold edges to obtain a triangular mesh model.

[0009] In combination with the first aspect, further, the method for obtaining the three-dimensional coordinates of all vertices in the triangular mesh model includes: taking the lower surface of the above clamping plate as the reference plane, the center of the circle of the lower surface of the above clamping plate as the origin, and taking the direction perpendicular to the reference plane as the upward direction. The positive direction of the axis is the horizontal projection plane of the fabric sample. Axis and The orthogonal plane of the axis is used to construct a three-dimensional coordinate system and obtain the three-dimensional coordinates of all vertices in the triangular mesh model.

[0010] In combination with the first aspect, further, according to the three-dimensional coordinates of all vertices in the triangular mesh model, the triangulated mesh model is divided into several independent and non-intersecting triangles using a triangulation algorithm, including: importing the three-dimensional coordinates of all vertices in the triangular mesh model into the programming software in the format of an array file, calling the triangulation algorithm, using the imported three-dimensional coordinate array file of all vertices as input parameters, generating several independent and non-intersecting triangles, and simultaneously generating the position index of the vertex of each triangle in the three-dimensional coordinate array file.

[0011] Combined with the first aspect, further, the calculation formula for the area of ​​each triangle is: ; in, Indicates the The area of ​​a triangle, 、 、 Respectively represent The vector cross product of the triangles is axis, axis, The axis weight, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

[0012] In combination with the first aspect, further, the calculation formula for the lateral displacement of the centroid of each triangle is: ; in, Indicates the The lateral displacement of the centroid of the triangle, Indicates the radius of the upper clamping plate, 、 Respectively represent The centroid of the triangle Axis coordinates, axis coordinates; The calculation formula for the longitudinal displacement of the centroid of each triangle is: ; in, Indicates the The longitudinal displacement of the center of mass of the triangle, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

[0013] In combination with the first aspect, further, the calculation formula for the overhang displacement of each triangle is: ; in, Indicates the The overhang displacement of the triangle, 、 Respectively represent The horizontal and vertical displacements of the centroid of the triangles; The calculation formula for the drape displacement of the fabric is: ; in, represents the drape displacement of the fabric, Indicates the The area of ​​a triangle, Represents the total number of triangles.

[0014] Combined with the first aspect, further, the calculation formula of the overhang potential of each triangle is: ; in, Indicates the The hanging potential of a triangle, Indicates the The longitudinal displacement of the center of mass of the triangle, represents the acceleration due to gravity; The calculation formula of the drape potential of the fabric is: ; in, represents the drape potential of the fabric, Indicates the The area of ​​a triangle, Represents the total number of triangles.

[0015] In a second aspect, the present invention provides a device for evaluating the three-dimensional drape performance of a fabric, comprising: The model building module is used to scan the three-dimensional drape form of the fabric, build a triangular mesh model, and divide the triangular mesh model into several independent and non-intersecting triangles using a triangulation algorithm based on the three-dimensional coordinates of all vertices in the triangular mesh model; a performance evaluation module, configured to calculate the area of ​​each triangle and the position data of the centroid of each triangle based on the three-dimensional coordinates of the vertices of each triangle, calculate a three-dimensional drape performance evaluation index of each triangle based on the position data of the centroid of each triangle, calculate a three-dimensional drape performance evaluation index of the fabric based on the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluate the three-dimensional drape performance of the fabric using the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

[0016] In a third aspect, the present invention provides a computer device, comprising: Storage medium for storing computer programs; A processor is used to execute the computer program to implement the method for evaluating the three-dimensional drape performance of fabrics according to the first aspect.

[0017] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for evaluating the three-dimensional drape performance of a fabric as described in the first aspect.

[0018] In a fifth aspect, the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the method for evaluating the three-dimensional drape performance of a fabric according to the first aspect.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The method for evaluating the three-dimensional drape performance of fabrics provided by the present invention constructs a triangular mesh model through three-dimensional scanning, divides the triangular mesh model into independent triangles using triangulation technology, and constructs a drape displacement calculation formula based on the lateral and longitudinal displacements of the centroid of each triangle and the area of ​​each triangle, or constructs a drape potential calculation formula based on the longitudinal displacement of the centroid of each triangle and the area of ​​each triangle. This realizes the quantitative analysis of the drape displacement distribution, solves the defect of traditional two-dimensional projection methods (such as the umbrella method) that cannot capture local wrinkle details, and provides a more stable and comprehensive quantitative basis for the drape performance evaluation of complex fabrics (such as blended fabrics). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1is a flow chart of a method for evaluating the three-dimensional drape performance of a fabric provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a triangular mesh model provided by an embodiment of the present invention; Figure 3 This is a partial mesh schematic diagram of the triangular mesh model provided by an embodiment of the present invention after triangulation, wherein plane 1 represents the reference plane, h1 and h2 respectively represent the longitudinal displacements of two triangles in the fabric relative to the reference plane, DGP1 and DGP2 respectively represent the draping potentials of the two triangles in the fabric, and g represents the acceleration of gravity. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods.

[0022] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0023] An embodiment of the present invention provides a method for evaluating the three-dimensional drape performance of a fabric, comprising: Scan the three-dimensional drape of the fabric to construct a triangular mesh model, and then use the triangulation algorithm to divide the triangular mesh model into several independent and non-intersecting triangles based on the three-dimensional coordinates of all vertices in the triangular mesh model; Calculating the area of ​​each triangle and the position data of the centroid of each triangle according to the three-dimensional coordinates of the vertices of each triangle, calculating the three-dimensional drape performance evaluation index of each triangle according to the position data of the centroid of each triangle, calculating the three-dimensional drape performance evaluation index of the fabric according to the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluating the three-dimensional drape performance of the fabric according to the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

[0024] The method for evaluating the three-dimensional drape performance of fabrics provided in an embodiment of the present invention can accurately characterize the three-dimensional morphology of fabrics, has clear physical meaning and high stability, and is a key breakthrough in solving the inherent defects of traditional two-dimensional methods such as lack of dimensionality and weak physical correlation. It is not only crucial for deepening the understanding of the fabric drape mechanism, but also has important practical significance for the research and development of new textile materials, the refined optimization of clothing technology, and the performance prediction of industrial fabrics.

[0025] Figure 1 This is a flow chart of a method for evaluating the three-dimensional drape performance of fabrics provided by an embodiment of the present invention. This flow chart only shows the logical sequence of the method of this embodiment. Different methods can be used without conflict. Figure 1 The steps shown or described are accomplished in the order shown.

[0026] The fabric drape performance evaluation method provided in an embodiment of the present invention can be applied to a terminal and can be executed by a fabric drape performance evaluation device, which can be implemented by software and / or hardware. The device can be integrated into a terminal, for example: any tablet computer or computer device with communication function.

[0027] An embodiment of the present invention provides a method for evaluating the three-dimensional drape performance of a fabric, comprising: Scan the three-dimensional drape of the fabric to construct a triangular mesh model, and then use the triangulation algorithm to divide the triangular mesh model into several independent and non-intersecting triangles based on the three-dimensional coordinates of all vertices in the triangular mesh model; The area of ​​each triangle and the lateral and longitudinal displacements of the center of mass of each triangle are calculated according to the three-dimensional coordinates of the vertices of each triangle. The drape displacement of each triangle is calculated according to the lateral and longitudinal displacements of the center of mass of each triangle. The drape displacement of the fabric is calculated according to the drape displacement of each triangle and the area of ​​each triangle. The three-dimensional drape performance of the fabric is evaluated by the drape displacement of the fabric.

[0028] In this embodiment, scanning the three-dimensional drape of the fabric and constructing a triangular mesh model specifically includes the following steps: Step 1: Cut a circular fabric sample with no creases, damage, and smooth edges within a preset distance from the edge of the fabric, cut a positioning hole at the center of the fabric sample, and evenly affix several reflective marking points on the surface of the fabric sample; Specifically, a circular fabric sample with a diameter of 240 mm, no creases, no damage and smooth edges is cut within 100 mm from the edge of the fabric, a positioning hole with a diameter of 1 mm is cut at the center of the fabric sample, 15 to 30 reflective marking points are evenly pasted on the surface of the fabric sample, and the spacing between adjacent marking points is set to 30 mm to 50 mm. The fabric sample is balanced in a standard atmospheric environment (temperature of 18°C ​​to 22°C, relative humidity of 61% to 69%) for humidity adjustment.

[0029] Step 2: Align the center of the fabric sample with the center of the upper and lower clamping plates of the drape tester. Pass the positioning pins of the lower clamping plate through the positioning holes of the fabric sample and the center hole of the upper clamping plate in sequence to clamp the fabric sample so that the fabric sample maintains a natural three-dimensional drape without pulling. Step 3: Scan the fabric sample at multiple angles to obtain complete three-dimensional drape data of the fabric sample; Specifically, a handheld 3D scanner is used to scan the fabric sample at multiple angles to obtain complete 3D draping morphology data of the fabric sample.

[0030] Step 4: Generate an initial triangular mesh model based on the complete three-dimensional drape shape data of the fabric sample; Specifically, the initial triangular mesh model of the scanning result in STL format is exported using three-dimensional scanning data processing software.

[0031] Step 5: Repair holes and clean up non-manifold edges on the initial triangular mesh model to obtain a triangular mesh model.

[0032] Specifically, the initial triangular mesh model is imported into the reverse engineering software for hole repair and non-manifold edge cleaning, and the following is obtained: Figure 2 The closed manifold triangular mesh model shown.

[0033] In this embodiment, the method for obtaining the three-dimensional coordinates of all vertices in the triangular mesh model specifically includes: taking the lower surface of the clamping plate as the reference plane, the center of the circle of the lower surface of the clamping plate as the origin, and taking the direction perpendicular to the reference plane as the upward direction. The positive direction of the axis is the horizontal projection plane of the fabric sample. Axis and The orthogonal plane of the axis is used to construct a three-dimensional coordinate system and obtain the three-dimensional coordinates of all vertices in the triangular mesh model.

[0034] Specifically, a three-dimensional coordinate system is constructed using reverse engineering software, and the three-dimensional coordinates of all vertices in the triangular mesh model are exported.

[0035] In this embodiment, the triangulation algorithm is used to divide the triangulated mesh model into a number of independent and non-intersecting triangles according to the three-dimensional coordinates of all vertices in the triangulated mesh model. Specifically, the three-dimensional coordinates of all vertices in the triangulated mesh model are imported into the programming software in the format of an array file, and the triangulation algorithm is called, with the imported three-dimensional coordinate array file of all vertices as input parameters to generate a number of independent and non-intersecting triangles, and at the same time, the position index of the vertex of each triangle in the three-dimensional coordinate array file is generated.

[0036] Specifically, the three-dimensional coordinates of all vertices in the triangular mesh model are imported into MATLAB software in the format of an array file, and the triangulation algorithm is called. In MATLAB software, the built-in delaunay triangulation function is called with the imported three-dimensional coordinate data file as the input parameter, or in the Python programming environment, the Delaunay function is called through the scipy.spatial library to generate a triangle set. Through the operation of the function, the triangle is generated. Independent and non-intersecting triangles, and output the position index of each triangle's vertex in the three-dimensional coordinate array file, that is, the position index of the three vertices corresponding to each triangle in the three-dimensional coordinate array file. Controlled within the range of 80,000 to 100,000.

[0037] In this embodiment, the definition The three vertices of a triangle 、 、 The coordinates of 、 、 , No. The centroid of the triangle The coordinates are ,in, , , .

[0038] The formula for calculating the area of ​​each triangle is: ; in, Indicates the The area of ​​a triangle in mm 2 , 、 、 Respectively represent The vector cross product of the triangles is axis, axis, The axis weight, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

[0039] Specifically, The edge vectors of the triangle are: ; No. The vector cross product of the triangles is: .

[0040] The calculation formulas for the lateral and longitudinal displacements of the centroid of each triangle are: ; in, 、 Respectively represent The horizontal and vertical displacements of the centroid of the triangle are in mm. Indicates the radius of the upper clamping plate, in mm. 、 Respectively represent The centroid of the triangle Axis coordinates, Axis coordinates.

[0041] Specifically, the radius of the upper clamping plate is 60 mm.

[0042] The calculation formula for the overhang displacement of each triangle is: ; in, Indicates the The overhang displacement of a triangle in mm.

[0043] The calculation formula for the drape displacement of the fabric is: ; in, Indicates the drape displacement of the fabric in mm. Represents the total number of triangles.

[0044] The drape displacement method provided in an embodiment of the present invention is used to evaluate the drape performance of two fabrics of different materials, specifically comprising the following steps: Step 1: Preparation of experimental materials and samples; This example selects two typical fabrics as test objects: Fabric 1: Bamboo fabric (100% bamboo fiber), weight 147g / m², representing traditional natural fiber fabric; Fabric 2: blended fabric (20% polyester, 69% rayon, 11% nylon), weight 136g / m², representing a common functional composite fabric.

[0045] Take 10 independent samples from each tissue (uniformly sized to be circular with a diameter of 36 cm), ensure that the samples are not damaged or wrinkled, and place them in a standard atmospheric environment for 24 hours before testing.

[0046] Step 2: Multi-method synchronous testing; In this embodiment, two methods are used to test the draping performance of each sample: The first is the standard drape coefficient method, which uses a fabric drape tester stand to fix the fabric and measure the drape form; The second method is the drape displacement method provided in this embodiment. The calculation formula for the drape displacement of the fabric is: .

[0047] Each method was tested 10 times on the same sample, and the discrete data of the test results were recorded.

[0048] Step 3: Comparative analysis of test result stability; In this example, the test stability was quantified by calculating the coefficient of variation (CV = standard deviation / average value × 100%) of the test results of 10 times using the two methods. The results are shown in Tables 1 and 2.

[0049] Table 1: Statistical comparison of different testing methods for bamboo fiber fabrics .

[0050] Table 2: Statistical comparison of different test methods for blended fabrics .

[0051] Step 4: Verify the conclusion.

[0052] Analyzing the data in Table 1 and Table 2 in this embodiment, it can be seen that: (1) The drape displacement method provided in this embodiment has significantly better test stability on different fabrics than the standard drape coefficient method: Bamboo fiber fabric: The coefficient of variation of the drape displacement method (0.61%) is 91.5% lower than that of the standard drape coefficient method (7.17%); Blended fabrics: The coefficient of variation of the drape displacement method (0.71%) is 90.6% lower than that of the standard drape coefficient method (7.56%); (2) The drape displacement method provided in this embodiment effectively reduces the influence of human operation errors and environmental interference in the standard drape coefficient method through refined modeling and potential quantification of three-dimensional point clouds, providing a more stable and reliable quantitative basis for drape performance evaluation.

[0053] An embodiment of the present invention provides a method for evaluating the three-dimensional drape performance of a fabric, comprising: Scan the three-dimensional drape of the fabric to construct a triangular mesh model, and then use the triangulation algorithm to divide the triangular mesh model into several independent and non-intersecting triangles based on the three-dimensional coordinates of all vertices in the triangular mesh model; The area of ​​each triangle and the longitudinal displacement of the center of mass of each triangle are calculated according to the three-dimensional coordinates of the vertices of each triangle. The drape potential of each triangle is calculated according to the longitudinal displacement of the center of mass of each triangle. The drape potential of the fabric is calculated according to the drape potential of each triangle and the area of ​​each triangle. The three-dimensional drape performance of the fabric is evaluated by the drape potential of the fabric.

[0054] In this embodiment, scanning the three-dimensional drape of the fabric and constructing a triangular mesh model specifically includes the following steps: Step 1: Cut a circular fabric sample with no creases, damage, and smooth edges within a preset distance from the edge of the fabric, cut a positioning hole at the center of the fabric sample, and evenly affix several reflective marking points on the surface of the fabric sample; Specifically, a circular fabric sample with a diameter of 240 mm, no creases, no damage and smooth edges is cut within 100 mm from the edge of the fabric, a positioning hole with a diameter of 1 mm is cut at the center of the fabric sample, 15 to 30 reflective marking points are evenly pasted on the surface of the fabric sample, and the spacing between adjacent marking points is set to 30 mm to 50 mm. The fabric sample is balanced in a standard atmospheric environment (temperature of 18°C ​​to 22°C, relative humidity of 61% to 69%) for humidity adjustment.

[0055] Step 2: Align the center of the fabric sample with the center of the upper and lower clamping plates of the drape tester. Pass the positioning pins of the lower clamping plate through the positioning holes of the fabric sample and the center hole of the upper clamping plate in sequence to clamp the fabric sample so that the fabric sample maintains a natural three-dimensional drape without pulling. Step 3: Scan the fabric sample at multiple angles to obtain complete three-dimensional drape data of the fabric sample; Specifically, a handheld 3D scanner is used to scan the fabric sample at multiple angles to obtain complete 3D draping morphology data of the fabric sample.

[0056] Step 4: Generate an initial triangular mesh model based on the complete three-dimensional drape shape data of the fabric sample; Specifically, the initial triangular mesh model of the scanning result in STL format is exported using three-dimensional scanning data processing software.

[0057] Step 5: Repair holes and clean up non-manifold edges on the initial triangular mesh model to obtain a triangular mesh model.

[0058] Specifically, the initial triangular mesh model is imported into reverse engineering software for hole repair and non-manifold edge cleaning to obtain a closed manifold triangular mesh model.

[0059] In this embodiment, obtaining the three-dimensional coordinates of all vertices in the triangular mesh model specifically includes: taking the lower surface of the clamping plate as the reference plane, the center of the circle of the lower surface of the clamping plate as the origin, and taking the direction perpendicular to the reference plane as the upward direction. The positive direction of the axis is the horizontal projection plane of the fabric sample. Axis and The orthogonal plane of the axis is used to construct a three-dimensional coordinate system and obtain the three-dimensional coordinates of all vertices in the triangular mesh model.

[0060] Specifically, a three-dimensional coordinate system is constructed using reverse engineering software, and the three-dimensional coordinates of all vertices in the triangular mesh model are exported.

[0061] In this embodiment, the triangulation algorithm is used to divide the triangulated mesh model into a number of independent and non-intersecting triangles according to the three-dimensional coordinates of all vertices in the triangulated mesh model. Specifically, the three-dimensional coordinates of all vertices in the triangulated mesh model are imported into the programming software in the format of an array file, and the triangulation algorithm is called to generate the following: Figure 3 The plurality of independent and non-intersecting triangles shown are generated, and the position index of the vertex of each triangle in the three-dimensional coordinate array file is generated at the same time.

[0062] Figure 3 In the figure, plane 1 represents the reference plane, which is used to define the initial plane position of the fabric and the spatial coordinate system of the gravity direction. h1 and h2 represent the longitudinal displacements of the two triangles in the fabric relative to the reference plane, DGP1 and DGP2 represent the draping potentials of the two triangles in the fabric, and g represents the acceleration due to gravity.

[0063] Specifically, the three-dimensional coordinates of all vertices in the triangular mesh model are imported into MATLAB software in the format of an array file, and the triangulation algorithm is called. In MATLAB software, the built-in delaunay triangulation function is called with the imported three-dimensional coordinate data file as the input parameter, or in the Python programming environment, the Delaunay function is called through the scipy.spatial library to generate a triangle set. Through the operation of the function, the triangle is generated. Independent and non-intersecting triangles, and output the position index of each triangle's vertex in the three-dimensional coordinate array file, that is, the position index of the three vertices corresponding to each triangle in the three-dimensional coordinate array file. Controlled within the range of 80,000 to 100,000.

[0064] In this embodiment, the definition The three vertices of a triangle 、 、 The coordinates of 、 、 , No. The centroid of the triangle The coordinates are ,in, , , .

[0065] The formula for calculating the area of ​​each triangle is: ; in, Indicates the The area of ​​a triangle in mm 2 , 、 、 Respectively represent The vector cross product of the triangles is axis, axis, The axis weight, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

[0066] Specifically, The edge vectors of the triangle are: ; No. The vector cross product of the triangles is: .

[0067] The calculation formula for the longitudinal displacement of the centroid of each triangle is: ; in, Indicates the The longitudinal displacement of the centroid of the triangle in mm.

[0068] The calculation formula of the overhang potential of each triangle is: ; in, Indicates the The pendant potential of a triangle, in J / kg, Indicates the acceleration due to gravity (9.8m / s 2 ).

[0069] The calculation formula of the drape potential of the fabric is: ; in, Indicates the draping potential of the fabric, in J / kg. Represents the total number of triangles.

[0070] In this embodiment, The formula derivation is based on the mass-area equivalence principle, including: The expression of fabric gravitational potential energy is: ,in, is the mass of the fabric in kg, is the acceleration due to gravity (9.8m / s 2 ), is the height of the center of mass, that is, the longitudinal displacement of the center of mass, in m; Depend on (in, is the area of ​​the fabric in mm 2 , The weight of the fabric in kg / m 2 ), converting the gravitational potential energy into ; The pendant potential per unit mass is defined as ; The calculation formula of the fabric's drape potential is obtained by integral summation and area normalization: ,in, The unit is J / kg.

[0071] The drape potential method provided in an embodiment of the present invention is used to evaluate the drape performance of two fabrics of different materials, specifically comprising the following steps: Step 1: Preparation of experimental materials and samples; This example selects two typical fabrics as test objects: Fabric 1: Pure cotton fabric, weight 240g / m², common cotton fabric, representing traditional natural fiber fabric; Fabric 2: blended fabric (54% viscose, 36.3% nylon, 9.7% spandex), weight 235g / m², representing a common functional composite fabric.

[0072] Take 7 independent samples from each tissue (uniformly sized to be circular with a diameter of 24 cm), ensure that the samples are not damaged or wrinkled, and equilibrate in a standard atmospheric environment for 24 hours before testing.

[0073] Step 2: Multi-method synchronous testing; In this embodiment, two methods are used to test the draping performance of each sample: The first is the standard drape coefficient method, which uses a fabric drape tester stand to fix the fabric and measure the drape form; The second method is the drape potential method provided in this embodiment. The calculation formula of the drape potential of the fabric is: .

[0074] Each method was tested on the same sample seven times, and the discrete data of the test results were recorded.

[0075] Step 3: Comparative analysis of test result stability; In this example, the coefficient of variation (CV = standard deviation / average value × 100%) of the test results of seven times using the two methods was calculated to quantify the test stability. The results are shown in Tables 3 and 4.

[0076] Table 3: Statistical comparison of different test methods for pure cotton fabrics .

[0077] Table 4: Statistical comparison of different test methods for blended fabrics .

[0078] Step 4: Verify the conclusion.

[0079] Analyzing the data in Table 3 and Table 4 in this embodiment, it can be seen that: (1) The drape potential method provided in this embodiment has significantly better test stability on different fabrics than the standard drape coefficient method: Cotton fabric: The coefficient of variation of the drape potential method (0.42%) is 86.7% lower than that of the standard drape coefficient method (3.16%); Blended fabrics: The coefficient of variation of the drape potential method (2.62%) is 73.3% lower than that of the standard drape coefficient method (9.83%); (2) The drape potential method provided in this embodiment effectively reduces the influence of human operation errors and environmental interference in the standard drape coefficient method through refined modeling and potential quantification of three-dimensional point clouds, providing a more stable and reliable quantitative basis for drape performance evaluation.

[0080] An embodiment of the present invention provides a device for evaluating the three-dimensional drape performance of a fabric, comprising: The model building module is used to scan the three-dimensional drape form of the fabric, build a triangular mesh model, and divide the triangular mesh model into several independent and non-intersecting triangles using a triangulation algorithm based on the three-dimensional coordinates of all vertices in the triangular mesh model; a performance evaluation module, configured to calculate the area of ​​each triangle and the position data of the centroid of each triangle based on the three-dimensional coordinates of the vertices of each triangle, calculate a three-dimensional drape performance evaluation index of each triangle based on the position data of the centroid of each triangle, calculate a three-dimensional drape performance evaluation index of the fabric based on the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluate the three-dimensional drape performance of the fabric using the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

[0081] The device for evaluating the three-dimensional drape performance of fabric provided by the embodiment of the present invention can execute the method for evaluating the three-dimensional drape performance of fabric provided by the embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0082] An embodiment of the present invention provides a computer device, including: Storage medium for storing computer programs; The processor is used to execute a computer program to implement the method for evaluating the three-dimensional drape performance of fabric provided by an embodiment of the present invention.

[0083] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for evaluating the three-dimensional drape performance of a fabric provided by the embodiment of the present invention is implemented.

[0084] This embodiment provides a computer program product, including a computer program. When the computer program is executed by a processor, the method for evaluating the three-dimensional drape performance of a fabric provided in the embodiment of the present invention is implemented.

[0085] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0086] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0087] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0089] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for evaluating the three-dimensional drape performance of a fabric, characterized in that: include: Scan the three-dimensional drape of the fabric to construct a triangular mesh model, and then use the triangulation algorithm to divide the triangular mesh model into several independent and non-intersecting triangles based on the three-dimensional coordinates of all vertices in the triangular mesh model; Calculating the area of ​​each triangle and the position data of the centroid of each triangle according to the three-dimensional coordinates of the vertices of each triangle, calculating the three-dimensional drape performance evaluation index of each triangle according to the position data of the centroid of each triangle, calculating the three-dimensional drape performance evaluation index of the fabric according to the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluating the three-dimensional drape performance of the fabric according to the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

2. The method for evaluating the three-dimensional drape performance of a fabric according to claim 1, wherein: Scanning the three-dimensional drape of the fabric and constructing a triangular mesh model include: Cut a circular fabric sample with no creases, no damage and smooth edges within a preset distance from the edge of the fabric, cut a positioning hole at the center of the fabric sample, and evenly stick several reflective marking points on the surface of the fabric sample; Align the center of the fabric sample with the center of the upper and lower clamping plates of the drape tester. Pass the positioning pins of the lower clamping plate through the positioning holes of the fabric sample and the center hole of the upper clamping plate in sequence. Clamp the fabric sample so that the fabric sample maintains a natural three-dimensional drape without pulling. Scan the fabric sample at multiple angles to obtain the complete three-dimensional drape data of the fabric sample; Generate an initial triangular mesh model based on the complete three-dimensional drape shape data of the fabric sample; The initial triangular mesh model is repaired with holes and cleaned with non-manifold edges to obtain a triangular mesh model.

3. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: The method for obtaining the three-dimensional coordinates of all vertices in the triangular mesh model includes: taking the lower surface of the clamping plate as the reference plane, the center of the circle on the lower surface of the clamping plate as the origin, and taking the direction perpendicular to the reference plane as the upward direction. The positive direction of the axis is the horizontal projection plane of the fabric sample. Axis and The orthogonal plane of the axis is used to construct a three-dimensional coordinate system and obtain the three-dimensional coordinates of all vertices in the triangular mesh model.

4. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: According to the three-dimensional coordinates of all vertices in the triangular mesh model, the triangular mesh model is divided into several independent and non-intersecting triangles using a triangulation algorithm, including: importing the three-dimensional coordinates of all vertices in the triangular mesh model into programming software in the format of an array file, calling the triangulation algorithm, using the imported three-dimensional coordinate array file of all vertices as input parameters, generating several independent and non-intersecting triangles, and simultaneously generating the position index of the vertex of each triangle in the three-dimensional coordinate array file.

5. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: The formula for calculating the area of ​​each triangle is: ； in, Indicates the The area of ​​a triangle, 、 、 Respectively represent The vector cross product of the triangles is axis, axis, The axis weight, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

6. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: The calculation formula for the lateral displacement of the centroid of each triangle is: ； in, Indicates the The lateral displacement of the centroid of the triangle, Indicates the radius of the upper clamping plate, 、 Respectively represent The centroid of the triangle Axis coordinates, axis coordinates; The calculation formula for the longitudinal displacement of the centroid of each triangle is: ； in, Indicates the The longitudinal displacement of the center of mass of the triangle, 、 、 Respectively represent The three vertices of a triangle Axis coordinates.

7. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: The calculation formula for the overhang displacement of each triangle is: ； in, Indicates the The overhang displacement of the triangle, 、 Respectively represent The horizontal and vertical displacements of the centroid of the triangles; The calculation formula for the drape displacement of the fabric is: ； in, represents the drape displacement of the fabric, Indicates the The area of ​​a triangle, Represents the total number of triangles.

8. The method for evaluating the three-dimensional drape performance of a fabric according to claim 2, wherein: The calculation formula of the overhang potential of each triangle is: ； in, Indicates the The hanging potential of a triangle, Indicates the The longitudinal displacement of the center of mass of the triangle, represents the acceleration due to gravity; The calculation formula of the drape potential of the fabric is: ； in, represents the drape potential of the fabric, Indicates the The area of ​​a triangle, Represents the total number of triangles.

9. A device for evaluating the three-dimensional drape performance of fabrics, characterized in that: include: The model building module is used to scan the three-dimensional drape form of the fabric, build a triangular mesh model, and divide the triangular mesh model into several independent and non-intersecting triangles using a triangulation algorithm based on the three-dimensional coordinates of all vertices in the triangular mesh model; a performance evaluation module, configured to calculate the area of ​​each triangle and the position data of the centroid of each triangle based on the three-dimensional coordinates of the vertices of each triangle, calculate a three-dimensional drape performance evaluation index of each triangle based on the position data of the centroid of each triangle, calculate a three-dimensional drape performance evaluation index of the fabric based on the three-dimensional drape performance evaluation index of each triangle and the area of ​​each triangle, and evaluate the three-dimensional drape performance of the fabric using the three-dimensional drape performance evaluation index of the fabric; Among them, when the position data of the center of mass is the lateral displacement and longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping displacement; when the position data of the center of mass is the longitudinal displacement of the center of mass, the corresponding three-dimensional draping performance evaluation index is the draping potential.

10. A computer device, characterized in that: include: Storage medium for storing computer programs; A processor, configured to execute the computer program to implement the method for evaluating the three-dimensional drape performance of a fabric according to any one of claims 1 to 8.

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